Apparatus of this type are widely used in the metal casting industry, and commonly comprise a plurality of metal casting units, all of which are similar in nature but supported at separate apertures in the table on spaced vertical axes thereof. In some apparatus, the liquid coolant discharge means take the form of a separate liquid coolant jacket about each casting unit, and a separate liquid coolant supply for the same; while in other apparatus, the liquid coolant discharge means take the form of a liquid coolant box, the housing of which defines the table and has spaced top and bottom housing members therein, which in turn have pairs of mutually opposing top and bottom apertures therein about spaced vertical axes of the box for the formation of the respective casting stations therebetween, and a chamber in the space between the housing members for supplying liquid coolant to the casting units at all of the respective stations. In each apparatus, each casting unit comprises an annular mold which has a vertical axis, upper and lower ends, an aperture extending therethrough between the ends thereof on the mold axis, an opening extending therethrough between the aperture and the outer periphery of the mold transverse the axis, and an annular flange relatively outturned about the mold axis on the outer periphery of the mold. Each mold is telescopically inserted in the table at the respective aperture or pair of apertures for the same, and coaxially thereof, to form the respective casting station, and is abutted against the table at the flange thereof, to receive support from the table. Moreover, where the liquid coolant discharge means take the form of a liquid coolant box, the housing of which has the aforedescribed features, the flange is commonly outstanding on one end portion of the mold at the outer periphery thereof, and the mold is telescopically inserted in the chamber of the box through the aperture in one of the top and bottom housing members, and abutted against the one housing member at the flange thereof, and against the other housing member about the aperture therein, so that in forming the casting station, the mold interfaces with the chamber at the opening in the mold transverse the axis thereof, for the discharge of the coolant therethrough. The reference in this regard to inserting the mold through the aperture in "one" of the housing members, takes into consideration that, as illustrated in U.S. Pat. No. 4,597,432, the flange may be outstanding on the lower end portion of the mold at the outer periphery thereof, and the mold may be telescopically inserted in the chamber through the bottom aperture of the box, and abutted against the bottom housing member at the flange thereof, and against the top housing member at the upper end portion thereof, so long as means are provided in the abutment interface between the upper end portion of the mold and the top housing member of the box, to form an annular seal between the two. In fact, as described in that Patent, the abutment interface commonly has a pair of annular seals formed thereabout in circumferentially extending lines of the interface which are relatively radially spaced apart from one another about the axis of the box and relatively offset from one another axially of the box, with a port interposed therebetween to intercept any liquid coolant which leaks from the chamber past the relatively radially outer seal of the interface in the direction of the axis of the box, and discharge the leakage coolant from the interface before the leakage coolant can penetrate the relatively radially inner seal thereof.
Some apparatus of the foregoing type also employ a combination wherein each mold is engaged with the table in an annulus about the respective axis of the table, the annulus has a fluid supply connection thereacross between the mold and the table, and the mold has an additional opening in one end portion thereof, and a fluid flow passage therewithin which is interconnected between the fluid supply connection and the additional opening to transmit fluid to the additional opening from the connection for discharge from the mold, relatively outside thereof. In U.S. Pat. Nos. 4,598,763 and 4,947,925, for example, the mold has an annular rabbet about the inner periphery thereof at the upper end thereof, the additional opening is formed in the axially extending wall of the rabbet, and the metal casting unit further comprises a ring of graphite or the like which is seated in the rabbet so that the fluid transmitted through the passage can be forced through the ring in the direction of the axis of the mold, to form an annulus of fluid about the molten metal body as it is cast within the aperture of the mold. See also U.S. Pat. Nos. 4,693,298, 5,040,595, and 5,119,883, wherein one or more fluids are transmitted through the body of the mold for carrying out still other functions in connection with the casting operation performed by the molds described therein.